Automatic electric brake.



EATENTED AUG. 21, was. A. L. mwmm AUTOMATIC ELEGTRIG BRAKE.

APPLIOATZON 11,211 MAY'T, 1904 2 SHEETS-SHEET 1.

I PATEHTED AUG! 21, 1906. UWELIUS.

AUTOMATIG ELECTRIC BRAKE.

APPLIUATION 2' LED MAX 7, 1904.

2 SHEETS-811E111 2.-

inventor:

siiding or skidding wheels sra'rn earners: orrrcn AUGUSTUS DUWELIUS, CINCINNATI, OHIO. AUTOMATBG ELEGTlC BRAKE.

ce ars.

fi e all whom it may concern:

vehicles-as, for instance, cars or trains of carsto apply a given amount of power to the brakes and to maintain or even increase th power applied until the vehicle has been brought to rest. The inefficiency of this method. of braking is due to the fact that insufficient power is a plied at the higher speeds an Y excess ower at the lower 'peeds of the moving ve '01s. The excessive power at the lower s eeds arrests the rotation'cf the wheels an causes them to slide or skid, thereby injuring them by destroying their rotundity and producing fiat ortions on their tread, causing them to be condemned as fiat wheels and removed from service. Moreover, the retarding effect of is less than that of wheels in rotation, the eatest effect being a point justbefore sli l ing takes place, for which reason a loss of time is experienced in the less prom t action of the braking mechanism when siding or skidding occurs. It is practically impossible to so vary the power manually as to conform to the rapid changes of conditions. 7

Broadly considered, my invention consists in automatically graduatin the braking power to conform to the varying speed of the vehicle during retardation, thereby securing the greatest possible retarding effect withinthe shortest time.

My invention is based upon the discovery that the relation existing between tlre speed i the vehicle and the electric current generby a series dynamot. e., a dynamo having itsfield in series with its armaturedriven by the rotation of-the traction-'geari. a, wheels or wheel-axles;of the vehicle, is sch as to produce the greatest retarding effect under all conditions and such as to avoid he sliding, and consequently the flattening, when the current generated is actuate a magnetic clutch connect- Specification of LSlZtGIB Patent. Application filed May 7, 1904- Serial No. 206,860.

Patented Aug. 21, 1908.

ing a brake-chain-winding drum with the brake-rigging.

In the accompanying drawings I have illustrated in Figure 1, partly in section and artly in elevation,

or practicing my invention. Figs. 2 and .3 represent detail views of the clutch and Winding-drum, on a larger scale. Referring to the drawings, A indicates a car frame or platform resting upon the wheeled trucks B C, the wheels of the trucks being provided with hand-brake rigging of any suitable character-as,.for instance, the brake-beams a, swinging hangers b, brakes shoes 0, brake-levers d, and brake-connecting rods e f. A chain 9, adapted to be wound upon the shaft 8 of a windin drum, serves to actuate the brake-rigging w en the magnetic clutch is energized by the dynamo.

In Figs. 2 and 3 'I have shown my preferred form of electromagnetic clutch composed of a three-flange spool-magnet M, driven by the axle G through the belt r and surrounded by. armature-bars A, havin their ends enga ed in the heads ofa drum adapted to revive with the spool and wind the brake-chain when the spool is operated by the current. The larger wheel 1) (shown in the drawings) and the shaft .9 of the wheel merely serve to multiply the power, being geared to the drum by a chain or belt t, as indicated. One of the car-Wheel axles-as, for instance, h-carr ies a fixed pulley E, which through the interm'ediacy of transmitting-gear-as, stance, the belts i 7' and counter shaft ltransmits the rotation of the axle to a series dynamo F, located on the car-floor. The current generated by the dynamo is transmitted by the wires m to the magnetic clutch when the switch at is closed. j

The m de of operationof the invention will be ap arent. When the brakes are to be applie the switch n is closed, thereby completing the circuit from the dynamoelectric machine F to the magnetic clutch. The current generated by the dynamo immediately actuates the magnetic clutch and starts the winding-drum shaft into operation, thereby winding the chain 9 and applythe particular brake-shoes governed thereby. As the speed of the car or train diminishes the current generated by the dyna-- mo diminishes correspondingly, so that the brakin power-of the electric motor is automatica ly graduated in accordance with the progressively-diminishing speed of the car or for in-.

6o a car provided with means I train un il the car or train comes to rest,

this-hr aking action beingefiected, quickly without shock or injury to the vehicle or its load and Without sliding or skidding.

Having thus described my invention, what I claim is 1. An automatic electric brake, consisting of a series dynamo, mechanism for driving .sc ihed.

-' 2; An automatie electric brake, consisting of-a series dynamo, mechanism ion driving said series dynamo from the traction-gear, a magnetic clutch actuated from saidv dynamo,

a winding-drum adapted to beconnected; with the traction-gear; of the car by said magnetic clutch, a brake-chain connected to the brake-operating lever and hand rbrake rigging likewise connected also to said'lever;

' substantially asdescribed:

3. An automatic electric brake, consisting of-a series. dynamo, mechanism for driving 'stantially as described.

4. An automatic electric brake consisting of a series dynamo, mechanism for driving the rotor of said dynamo from, the traction geanat a higherspeedthan said gear a bralw chain-winding drum normally discoimeeted from the traction gean, and; intermediate connections for driving the winding drumfrom the-trection-gearat a less speed: than said gear but with an increment of pow-en, said intermediate connections includin a magnetic clutch adapted to be operated y the 'dynamocurrent; substantially as de scribed.

In testimony whereof I afiix my signature in presence of two witnesses AUGUSTUS L. ELWIELIUS; Witnesses W. S. LITTLE, Hermon Hi A LEN. 

